1. Field of the Invention
The present invention relates to an electrical connector capable of preventing plugging error with any connector other than a mating connector.
2. Description of the Related Art
This kind of connector is disclosed, for example, in Japanese Patent Application Kokai Number 6-60077 (Patent Document 1).
The convention connector has a plugging face which has a sectional shape of oblong square tube taken along the plane perpendicular the plugging direction. A rugged portion is provided at a corner of the upper surface of the plugging face to prevent plugging error. The connector comprises coaxial cables at ends in the horizontal direction and a plurality of signal terminals arranged between the coaxial cables.
In the convention connector, however, there have been problems in terms of manufacturing accuracy and plugging deviation caused by the plugging face having the shape of square tube.
A molding die for the housing requires two directional dimensions, vertical and horizontal dimensions with respect to the plane perpendicular to the plugging direction, for the square tubular shape. Accordingly, dimensional errors in the two directions are possible. Consequently, the dimensional error of the conventional connector is larger than that of other connector having a cylindrical shape which requires only one dimension, a radius from the center.
In the conventional connector with the square tubular shape, when plugged with the mating connector, even if the connectors fit in each other in the vertical direction, a plugging error is possible because of the plugging deviation in the horizontal direction. However, in case of a connector with the cylindrical plugging shape, even if there is a plugging deviation in the horizontal error, the plugging deviation of a certain part of the plugging face is small and the amount of the plugging deviation is changing continuously from the part of the small deviation so that it is possible to lead to proper plugging without plugging deviation by correcting the deviation at that part.
As described above, the conventional connector having the plugging face of square tubular shape has a large error in the manufacturing accuracy and no correction capability for the plugging deviation. Accordingly, unless a key groove for a key is made sufficiently large to absorb the manufacturing error and plugging deviation, the smooth plugging is impossible. However, when a plurality of keys are necessary, it is impossible to provide many keys densely in a limited area because the respective keys require a sufficient interval between each other.